Wireless communication device

ABSTRACT

A wireless communication device is equipped with a first housing having a first circuit board; a second housing that is provided at one end of the first housing so as to freely open and close with respect to the first housing and that has a second circuit board and an audio input section; and a third housing that is provided at the other end of the first housing so as to be reclosably open with respect to the first housing and that has a third circuit board and an audio output section. A portion of the second housing overlaps a portion of the first housing while the second housing remains open with respect to the first housing. The first housing has a first conductive terminal disposed at a position on the first circuit board that overlaps a portion of the second housing while the second housing remains open with respect to the first housing. The second housing has a second conductive terminal, which is electrically connected to the first conductive terminal while the second housing remain open, at a position on the second circuit board that overlaps a portion of the first housing while the second housing remains open with respect to the first housing. The first circuit board has a power feeding section. The first circuit board and the second circuit board makeup a dipole antenna when the second housing is opened with respect to the first housing.

TECHNICAL FIELD

The present invention relates to a wireless communication device thatexerts a small effect on a human body and that exhibits high antennaperformance.

BACKGROUND ART

The number of applications installed in a portable phone recentlyincreases, and a user's usage pattern also becomes diversified. Althougha straight type and a folding type have hitherto been dominant as ahousing structure of a portable phone, portable phones having newhousing structures, such as a slide type structure and a two-axisturning type structure, have therefore been contrived. As mentionedabove, the housing structure of an electronic device, such as a portablephone, is always experiencing evolution, and contrivance of another newhousing structure is expected in future.

For instance, a sliding portable phone 600A, which is shown in FIG. 7described in Patent Document 1, includes a main housing 100 having atleast a display section 101 and input operation sections 102A and 102B,a first movable housing 610A that has a transmitter section 611 and thatis slidably engaged with an upper portion of the main housing 100, and asecond movable housing 620A that has a receiver section 621 and that isslidably engaged with a lower portion of the main housing 100. When boththe first movable housing 610A and the second movable housing 620A arein a closed state, both the movable housings 610A and 620A cover theentirety of the display section 101 and the input operation sections102A and 102B of the of the main housing 100.

The electronic device having a wireless communication function, like aportable phone, has an antenna. Since the performance of the antenna isaffected by the type of an adopted antenna or the layout of an antennain an housing, the antenna must separately be designed in conformancewith an housing structure of an electronic device so that the antennacan exhibit appropriate performance.

For instance, a folding wireless communication device, which is shown inFIG. 8 described in Patent Document 2, has a dipole antenna 2 providedon a first housing 5 and a conductor 12 provided on a second housing 8.The conductor 12 is provided so as to oppose the dipole antenna 2 whilethe housing is folded and acts as a passive element. Therefore,deterioration of an impedance characteristic of the antenna, which wouldotherwise arise while the housing is folded, is prevented, so that astable antenna characteristic can be exhibited. According to PatentDocument 1, the effect is not limited to the folding wirelesscommunication device having two housings shown in FIG. 8 and alsoimplemented by a folding wireless communication device having threehousings shown in FIG. 9.

In a portable phone shown in FIG. 10 described in Patent Document 3, anantenna housing section 14 made from a nonconductive member into a boxshape is disposed at a step 11B formed on an upper end on the back of anhousing case 11 so as to be slidably in a vertical direction. Aninverted-F antenna element making up a plate-like inverted-F antenna(PIFA) is held in the antenna housing 14. When inserted in the step 11B,the antenna housing section 14 operates as a PIFA. On the contrary, whenpulled out of the step 11B, the antenna housing section operates as amonopole antenna. The antenna that comes in different types according tothe status of the antenna housing section 14 is thus employed in theportable phone.

Patent Document 1: JP-A-2004-72285

Patent Document 2: JP-A-10-84406

Patent Document 3: JP-A-2002-176307

DISCLOSURE OF THE INVENTION Problem that the Invention is to Solve

A specific absorption rate (SAR) is available as an index for evaluatinginfluence of an electromagnetic wave transmitted from a wirelesscommunication device on a human body. An SAR value shows the amount ofenergy absorbed by a unit mass of tissue during a unit time and makes itpossible to ascertain the amount of energy that the human body hasreceived from a wireless communication device for a given period oftime. In particular, a local SAR is used for a portable phone that isused nearby a human head. A portable phone exhibiting a large SAR valueexerts a great effect on a human body during a call and undergoesunfavorable degradation of call performance attributable to absorptionof energy. If an antenna output is reduced, the SAR value will becomesmaller. However, when the antenna output is small, performance of theportable phone is deteriorated. For this reason, a portable phone thatexhibits a small SAR value and that exhibits high performance isdesirable.

When a dipole antenna is used, high performance is obtained over a widefrequency band. A wireless communication device, such as a portablephone having a dipole antenna, is therefore desirable.

An object of the present invention is to provide a wirelesscommunication device that exerts little effect on a human body during aphone and that exhibits high antenna performance.

Means for Solving the Problem

The present invention provides a wireless communication devicecomprising: a first housing having a first circuit board; a secondhousing provided at one end of the first housing so as to freely openand close with respect to the first housing and that has a secondcircuit board and an audio input section; and a third housing providedat the other end of the first housing so as to freely open and closewith respect to the first housing and that has a third circuit board andan audio output section. A portion of the second housing overlaps aportion of the first housing in a state that the second housing isopened with respect to the first housing. The first housing has a firstconductive terminal disposed at a position on the first circuit board.The position on the first circuit board overlaps a portion of the secondhousing in a state that the second housing is opened with respect to thefirst housing. The second housing has a second conductive terminal whichis electrically connected to the first conductive terminal in a statethat the second housing is opened with respect to the first housing, thesecond conductive terminal disposed at a position on the second circuitboard that overlaps a portion of the first housing in a state that thesecond housing is opened with respect to the first housing. The firstcircuit board has a power feeding section. The first circuit board andthe second circuit board are configured as a dipole antenna when thesecond housing is opened with respect to the first housing.

In the wireless communication device, the second housing has an antennaelement having a third conductive terminal electrically connected to thefirst conductive terminal in a state that the second housing is closedwith respect to the first housing.

In the wireless communication device, the antenna element serves as amonopole antenna when the second housing is opened with respect to thefirst housing.

In the wireless communication device, the power feeding section isprovided at a position on the first circuit board that overlaps aportion of the second housing in a state that the second housing isopened with respect to the first housing.

In the wireless communication device, the third housing has a thirdcircuit board connected to the second circuit board through an inductor.

In the wireless communication device, the second housing and the thirdhousing slide over the first housing to move to an open state or anclosed state.

In the wireless communication device, a signal processing section thatperforms signal processing for wireless communication using the dipoleantenna or the monopole antenna is provided on the first circuit board.

ADVANTAGE OF THE INVENTION

According to a wireless communication device of the present invention,the first circuit board and the second circuit board are configured asthe dipole antenna in a state that the second housing and the thirdhousing are opened with respect to the first housing. When the usermakes a phone call while holding an audio output section to his/her earin the open state, a distance from the user's head to a power feedingsection is long; hence, an SAR value becomes low. Consequently, it ispossible to provide a wireless communication device that exerts littleeffect on a human body during a phone call and that exhibits highantenna performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1( a) is a front view and FIG. 1( b) is a side cross sectional viewshowing a wireless communication device of a first embodiment.

FIG. 2 is a side cross sectional view of the wireless communicationdevice that makes an electrical connection utilizing capacity coupling.

FIG. 3 is a view showing a positional relationship between the wirelesscommunication device of the first embodiment and a user's head when theuser carries out a phone call while a second housing and a third housingare opened with respect to a first housing.

FIG. 4 is a view showing a positional relationship between the wirelesscommunication device of the first embodiment and the user's head whenthe user carries out a phone call with the second housing being openedand the third housing being closed with respect to the first housing.

FIG. 5 is a side cross sectional view showing a wireless communicationdevice of a second embodiment.

FIG. 6 is a side cross sectional view showing a wireless communicationdevice in which the third housing is eliminated from the wirelesscommunication device of the first embodiment.

FIG. 7 is a view showing a sliding portable phone described inJP-A-2004-72285.

FIG. 8 is a view showing a folding wireless communication device twohousings that is described in JP-A-10-84406.

FIG. 9 is a view showing a folding wireless communication device havingthree housings that is described in JP-A-10-84406.

FIG. 10 is a view showing a portable phone described inJP-A-2002-176307.

DESCRIPTIONS OF THE REFERENCE NUMERALS AND SYMBOLS

110 FIRST HOUSING

113 FIRST CIRCUIT BOARD

115 CONDUCTIVE TERMINAL

117 POWER FEEDING SECTION

120 SECOND HOUSING

121 SECOND CIRCUIT BOARD

123 MONOPOLE ANTENNA

125 MICROPHONE

127 CONDUCTIVE TERMINAL

129 CONDUCTIVE TERMINAL

130 THIRD HOUSING

131 THIRD CIRCUIT BOARD

133 SPEAKER

151 ANTENNA ELEMENT

153 CONDUCTIVE TERMINAL

155 CONDUCTIVE SECTION

157 CONDUCTIVE PLATE

BEST MODES FOR IMPLEMENTING THE INVENTION

Embodiments of the present invention are hereinbelow described byreference to the drawings.

First Embodiment

FIG. 1 is a block diagram showing a wireless communication device of afirst embodiment. FIG. 1( a) is a front view showing the wirelesscommunication device in an open state, and FIG. 1( b) is a side crosssectional view showing the wireless communication device in the openstate. As shown in FIG. 1, the wireless communication device of thefirst embodiment has a first housing 110, a second housing 120, and athird housing 130. The second housing 120 and the third housing 130 areprovided so as to be able to slide over the first housing 110 and so asto be opened and closed with respect to the first housing 110. The firsthousing 110 has a display section 111. When the second housing 120 andthe third housing 130 are closed with respect to the first housing 110,the display section 111 is covered with the second housing 120 and thethird housing 130. If the length of the first housing 110 is taken asP1; the length of the second housing 120 is taken as P2; and the lengthof the third housing 130 is taken as P3, a relationship amonglongitudinal lengths of the respective housings is defined as P1>P2≈P3.

The first housing 110 has therein a first circuit board 113 which isprovided on the back of the display section 111. The first circuit board113 has a signal processing section that performs signal processing forthe purpose of wireless communication. The signal processing sectionprocesses a high-frequency signal. The second housing 120 has therein asecond circuit board 121, a monopole antenna 123, and a microphone 125.The third housing 130 has therein a third circuit board 131 and aspeaker 133. The third circuit board 131 and the first circuit board 113are connected together by means of an unillustrated inductor. Theinductor reduces influence of high frequency noise, which is generatedfrom the first circuit board 113, on the third circuit board 131.

A conductive terminal 115 is provided on a face of the first circuitboard 113 included in the first housing 110, the face of the firstcircuit board 113 opposing to the second housing 120. Meanwhile, aconductive terminal 127 is provided on a face of the second circuitboard 121 included in the second housing 120, the face of the secondcircuit board 121 opposing to the first housing 110. The conductiveterminal 127 contacts the conductive terminal 115 when the secondhousing 120 is opened with respect to the first housing 110 (hereinaftersimply called an “open state”) Each of the conductive terminal 127 andthe conductive terminal 129 has a spring. An end portion which iscontacted with the conductive terminal 115 is extended and contracted bythe spring.

A connection between the conductive terminal 115 and the conductiveterminals 127 and a connection between the conductive terminal 115 andthe conductive terminals 129 are not limited to the connectionimplemented by expansion and contraction of the spring. As shown in FIG.2, the connection may also be implemented by an electrical connectionutilizing capacity coupling. In the case of an electrical connectionutilizing capacity coupling, each of the conductive terminals 115, 127,and 129 has an area that enables performance of capacity coupling. Theconductive terminals are placed at positions where the conductiveterminal 115 and the conductive terminal 127 overlap each other inparallel at an open state and where the conductive terminal 115 and theconductive terminal 129 overlap each other in parallel at a closedstate. The conductive terminals can assume any shape, so long as overlapareas of each of the conductive terminals can be assured.

In a configuration in which the conductive terminals are connected bymeans of expansion and contraction of the spring, the conductiveterminals remain uncovered. However, in a form of an electricalconnection utilizing capacitive coupling, the conductive terminalsoperate even while covered with the housing, so that design limits canbe lessened.

As shown in FIG. 1, even in an open state, the second housing 120 andthe third housing 130 partially overlap the first housing 110, and thefirst circuit board 113 and the second circuit board 121 also partiallyoverlap each other. The conductive terminal 115 on the first circuitboard 113 and the conductive terminal 127 on the second circuit board121 are disposed at areas where the first circuit board 113 and thesecond circuit board 121 overlap each other in the open state.Specifically, the conductive terminal 115 is disposed in the vicinity ofan area above the end of the first circuit board 113 close to the secondhousing 120. The conductive terminal 127 is disposed in the vicinity ofan area above the end of the second circuit board 121 close to the firsthousing 110.

Further, a power feeding section 117 is disposed at a position on thefirst circuit board 113 within the overlap area between the firstcircuit board 113 and the second circuit board 121 in the open state. Inthe open state, the conductive terminal 115 on the first circuit board113 and the conductive terminal 127 on the second circuit board 121contact each other. Therefore, the first circuit board 113 and thesecond circuit board 121 are configured as a dipole antenna. Meanwhile,in the closed state, the conductive terminal 115 on the first circuitboard 113 and the conductive terminal 129 of the monopole antenna 123contact each other. Hence, power is fed from the power feeding section117 to the monopole antenna 123.

As mentioned above, in the wireless communication device of the presentembodiment, the dipole antenna configured by the first circuit board 113and the second circuit board 121 is used in the open state, and themonopole antenna 123 is used in the closed state. The dipole antennaexhibits high performance over a wide frequency band when compared withthe monopole antenna. Therefore, the wireless communication device ofthe present embodiment is opened, whereby high performance can beachieved over a wider frequency band than the frequency band in a statethat the wireless communication device is closed.

FIG. 3 is a view showing a positional relationship between the wirelesscommunication device of the first embodiment and a user's head when theuser carries out a phone call while the second housing 120 and the thirdhousing 130 are opened with respect to the first housing 110, FIG. 4 isa view showing a positional relationship between the wirelesscommunication device of the first embodiment and a user's head when theuser carries out a phone call with the second housing 120 being openedand the third housing 130 being closed with respect to the first housing110. As shown in FIGS. 3 and 4, distances (D1, L1) from the head to thepower feeding section 117 in the state shown in FIG. 3 are longer thandistances (D2, L2) from the head to the power feeding section 117 in astate shown in FIG. 4. As the power feeding section 117 is separatedfrom the head, the SAR value become smaller and the phone performance isalso increased. Therefore, when the user makes a phone call, it isbetter to bring the wireless communication device of the embodiment intoa state shown in FIG. 3; namely, a state in which the second housing 120and the third housing 130 are opened with respect to the first housing110.

The embodiment describes the monopole antenna 123 as an example antennaused with the second housing 120 being closed with respect to the firsthousing 110. However, a loop antenna or a plate inverted F antenna(PIFA) can also be employed in place of the monopole antenna 123.

Second Embodiment

FIG. 5 is a side cross sectional view showing a wireless communicationdevice of a second embodiment. The wireless communication device of thesecond embodiment differs from the wireless communication device of thefirst embodiment in that the second embodiment is additionally providedwith a configuration for increasing an effective volume of the antennautilized when the second housing 120 is closed with respect to the firsthousing 110. The second embodiment is analogous to the first embodimentin other respect, and constituent elements shown in FIG. 5, which arealso common to FIG. 1, are assigned the same reference numerals.

The second housing 120 of the present embodiment has therein an antennaelement 151 having the same shape (a rectangular shape) as that of themonopole antenna 123 described in the first embodiment. A conductiveterminal 129 is provided at one end of the antenna element 151, and aconductive terminal 153 is provided at the other end. The conductiveterminal 129 provided at one end of the antenna element 151 contacts theconductive terminal 115 on the first circuit board 113 in the closedstate.

The first housing 110 of the present embodiment has therein arectangular conductive plate 157 in addition to the first circuit board113. The conductive plate 157 is insulated from the first circuit board113. A conductive section 155 is provided at a position on theconductive plate 157 where the conductive section contacts theconductive terminal 153 of the antenna element 151 in the closed state.The conductive terminal 153 provided at the other end of the antennaelement 151 contacts the conductive section 155 of the conductive plate157 in the closed state.

According to the foregoing configuration, the constituent elementutilized as the antenna in the closed state is not limited to theantenna element 151. The conductive plate 157 provided on the firsthousing 110 is also included in the constituent element utilized as theantenna. Therefore, an effective volume of the antenna that is largerthan the effective volume of the monopole antenna 123 described in thefirst embodiment can be assured. Since the effective volume of theantenna is large, sensitivity is enhanced. Therefore, high performanceantenna can be utilized even in the closed state.

The wireless communication devices described in the first and secondembodiments in the above have the slidable second housing 120 and theslidable third housing 130 that are provided at both ends of the firsthousing 110. However, as shown in FIG. 6, the third housing 130 may alsobe eliminated. Moreover, in the first and second embodiments, the secondhousing 120 and the third housing 130 are slid to open and close withrespect to the first housing 110. However, there can also be adopted astructure in which hinges are provided at both ends of the first end110, to thus enable the second housing 120 and the third housing 130 toopen and close with respect to the first housing 110 like a gatefold.

Although the present invention has been described in detail by referenceto the specific embodiments, it is manifest to those skilled in the artthat the present invention be susceptible to various alterations andmodifications without departing the spirit and scope of the invention.

INDUSTRIAL APPLICABILITY

A wireless communication device of the present invention is useful as aportable phone, or the like, that exerts little effect on a human bodyduring a phone call and that exhibits high antenna performance.

1. A wireless communication device comprising: a first housing having afirst circuit board; a second housing provided at one end of the firsthousing so as to freely open and close with respect to the first housingand that has a second circuit board and an audio input section; and athird housing provided at the other end of the first housing so as tofreely open and close with respect to the first housing and that has athird circuit board and an audio output section, wherein respectivelengths of the second and third housings are smaller than a length ofthe first housing in an opening and closing direction; wherein thesecond housing is away from a head of a user than the third housing whenthe user makes a phone call; wherein a portion of the second housingoverlaps a portion of the first housing in a state that the secondhousing is opened with respect to the first housing; wherein the firsthousing has a first conductive terminal disposed at a position on thefirst circuit board, the position on the first circuit board beingoverlapping a portion of the second housing in a state that the secondhousing is opened with respect to the first housing; wherein the secondhousing has a second conductive terminal which is electrically connectedto the first conductive terminal in a state that the second housing isopened with respect to the first housing, the second conductive terminaldisposed at a position on the second circuit board that overlaps aportion of the first housing in a state that the second housing isopened with respect to the first housing; wherein the first circuitboard has a power feeding section; and wherein the first circuit boardand the second circuit board are configured as a dipole antenna when thesecond housing is opened with respect to the first housing.
 2. Thewireless communication device according to claim 1, wherein the secondhousing has an antenna element having a third conductive terminalelectrically connected to the first conductive terminal in a state thatthe second housing is closed with respect to the first housing.
 3. Thewireless communication device according to claim 2, wherein the antennaelement serves as a monopole antenna when the second housing is openedwith respect to the first housing.
 4. The wireless communication deviceaccording to claim 1, wherein the power feeding section is provided at aposition on the first circuit board that overlaps a portion of thesecond housing in a state that the second housing is opened with respectto the first housing.
 5. The wireless communication device according toclaim 1, wherein the third housing has a third circuit board connectedto the second circuit board through an inductor.
 6. The wirelesscommunication device according to claim 2, wherein the second housingand the third housing slide over the first housing to move to an openstate or an closed state.
 7. The wireless communication device accordingto claim 3, wherein a signal processing section that performs signalprocessing for wireless communication using the dipole antenna or themonopole antenna is provided on the first circuit board.